Load proportioning means for internal combustion engines



Dec. 24, 1957 N. M. REINERS 2,817,211

LOAD PROPORTIONING MEANS FOR INTERNAL COMBUSTION ENGINES Filed May 20, 1955 4 Sheets-Sheet l (\i Q E I; Q 2 i 5? s INVEN TOR.-

Yez/L'ZZeMReLnem Dec. 24, 1957 N. M. REINERS LOAD PROPORTIONING MEANS FOR INTERNAL COMBUSTION ENGINES Filed May 20. 1955 4 Sheets-Sheet 2 5, 6 mm sw a QR W m M i My S mm ww Q Q Q wk Q S N Dec. 24, 1957 2,817,211

LOAD PROPORTIONING MEANS FOR INTERNAL COMBUSTION ENGINES Filed May 20, 1955 N. M. REINERS 4 Sheets-Sheet 3 m m E Wm M Q i I I We Lw WQMI m \QN QQN. mm M Q wm @m QQN mm Dec. 24, 1957 N. M. REINERS LOAD PROPORTIONING MEANS FOR INTERNAL COMBUSTION ENGINES 4 Sh ets-Sheet 4 Filed May 20, 1955 N 02 m2 w2m I INVENTOR.

Mffellnera, 9: 5460 22 LOAD PROPORTIONHNG MEANS FOR INTERNAL COMBUSTION ENGINES Neville M. Reiners, Columbus, ind, assignor to Cummins Engine Company, Inc., Columbus, Ind., a corporation of Indiana Application May 20, 1955, Serial No. 509,735

20 Claims. (Cl. fill-97) The invention relates to multiple engine operation and more particularly to a means for proportioning the load between two or more engines of the internal combustion type.

The general object of the invention is to provide a novel load proportioning means adapted for use with two or more engines where the engines are all rigidly connected to a single driven element or where they are non-rigidly connected to such an element or where each drives a separate driven element.

Another object is to provide a novel load proportioning means of the foregoing character, which may be constructed for equally proportioning the load between two or more engines of equal size and rating or may be constructed to properly proportion the load between two or more engines of unequal size and rating.

It is also among the objects of the invention to provide a novel load proportioning means for a multiple engine installation, which permits operation of any engine of such installation alone, which provides satisfactory engine operation at idling speed either when one engine alone is operating or when all are operating, and which permits full governor control of the respective engines at idling and maximum speeds.

Other objects and advantages will become apparent from the following description taken in connection with the accompanying drawings, in which:

Fig. l is an elevational view, partially diagrammatic, of two engines of the diesel type having fuel supply apparatus of the type shown in my copending application Serial No. 338,646, filed February 25, 1953, now Patent No. 2,727,498, and having load proportioning means embodying the features of the invention;

Fig. 2 is a longitudinal sectional view of the load proportioning means illustrated in Fig. 1;

Fig. 3 is a view similar to Fig. 2 but showing a modified form of load proportioning means;

Figs. 4, 5 and 6 illustrate another modified form of load proportioning means, the respective figures of this group illustrating the parts in different positions under different conditions of operation;

Fig. 7 is a View similar to Fig. 2 but showing still another modified form of load proportioning means;

Figs. 8 and 9 are longitudinal sectional views of still another modified form of load proportioning means, the two figures showing the parts in different positions under different conditions of operation, and

Fig. 10 is an elevational view of two engines of different size, having a load proportioning means of the form shown in Fig. 7.

It is frequently desirable to utilize two or more engines as a driving means, to provide for wide variations in power delivered. In such installations, if the two engines are of equal size and both are operating, it is of course desirable that the load be equally proportioned between the two engines. In other instances, it may be desirable to provide two or more engines of different size with each engine carrying a predetermined portion of the load,

States Patent The drives of such engines may be rigidly connected together or they may have a non-rigid connection or may not have any connection at all. An example of two eugines rigidly connected together is where their drive shafts are connected through gearing or the like to a single driven shaft. Such gearing of course may include clutches for the individual engines so that either engine may be disconnected when it is desired to operate one engine alone. An example of the case where the drives of two engines are connected together but in a non-rigid manner is where the drive shafts of the two engines are connected to a torque converter which in turn operates a driven shaft. An example of the case where the drive shafts of the two engines have no connection with each other is a marine installation where each engine drives an individual screw. The load proportioning means disclosed herein may be used in any of these instances.

A load proportioning means embodying the features of the invention is also adapted for use with different types of engines. Thus it may be used with diesel engines Where the engine power is proportional to the fuel pressure. It may also be used with gasoline engines 01 turbocharged diesel engines where the power is a function of the intake manifold pressure. In the case of diesel engines where the engine power is proportional to the fuel pressure, the present invention is also adapted for use with different types of fuel systems for supplying fuel under pressure to the engine cylinders.

A load proportioning means according to the present invention is capable of maintaining a predetermined proportion of the total load on the respective engines throughout the speed range of the engines, and the engines will idle satisfactorily. The load proportioning means may be used with engines provided with either the automotive type or the tractor type of governor, and full over-speed governor control is permitted under all conditions of operation. Furthermore, the present load proportioning means permits single engine operation of either engine of the multiple installation at full or partial loads without necessitating any revision of the engine installation or control linkage.

One embodiment of the invention is shown in Fig. 2, and the manner in which it is applied to two engines of equal size is illustrated in Fig. 1 of the drawings. In this instance, the diesel engines illustrated are provided with fuel supply apparatus of the type shown in my said copending application Serial No. 338,646, now Patent No. 2,727,498. For purposes of illustration, only two engines are shown but the invention is applicable to more than two engines by merely repeating the apparatus and connecting it in a manner as will hereinafter be described. The two engines shown in Fig. 1 of the drawings do not indicate how their drive shafts are connected, since this fact does not affect the operation of the load proportioning means. Since the two engines shown in these figures are of equal size, the load proportioning means is arranged to equally proportion the load between them.

To facilitate description of the invention, I have labeled the left-hand engine in Fig. 1 as Engine No. l and the right-hand engine as Engine No. 2. In this figure, the fuel for the engines is shown as being supplied from a common tank 2% having a supply line 21 provided with two branches 22 and 23 leading to the fuel supply apparatus, indicated generally at 24, of the respective engines. As disclosed in my said copending application, the fuel supply apparatus 24 for each engine draws fuel from the tank 20 and supplies it to a common supply rail 25 under predetermined variable pressure. In the case of engine No. 1, the fuel supply apparatus 24 supplies the fuel to the common rail 25 through a line 26 provided with a shutoff valve 27. in the case of engine No. 2, the fuel supply apparatus 24 therefor supplies the fuel to the common supply rail 25 through a line connected to a load proportioning means, indicated generally at 31, embodying the features of the invention. From the load proportioning means 31 the fuel flows through a line 32 to the common supply rail 25 for engine No. 2, the line 32 including a shutoff valve 33.

Fuel supplied to the common supply rail 25 of each engine is transmitted through branch lines to a plurality of injectors (not shown), one for each cylinder, and fuel returned from the injectors is collected in a common return line 34 which is connected through a line 35 for return of the fuel to the tank 20. The line 35 of each engine is also connected to the fuel supply apparatus 24 thereof for return of bypassed fuel to the tank 20.

Each fuel supply apparatus 24 is provided with a throttle control lever 36, the levers 36 of the two engines being connected for simultaneous movement by a link 37. The two throttle levers 36 may be moved by a master throttle 40 which in the present instance is shown as being connected to the throttle lever 36 of engine No. l by a link 41. The setting of the throttle lever 36 for engine No. 2 is such that a slightly higher pressure of the fuel is provided than for engine No. 1, for any setting of the master throttle 40, for reasons that will hereinafter appear.

device is applied to a gasoline engine or a turbo-charged diesel engine where the power delivered by the engine is a function of the air pressure in the intake manifold, the load proportioning means is connected to respond to such pressure. In the present instance where diesel engines are shown, without any turbocharger, and where the engine power is proportional to the pressure of the fuel supplied to the cylinders, the apparatus is connected so that it is responsive to such fuel pressures. Two engines of the same design will deliver substantially the same power when the pressures of the fuel supplied to the cylinders of the engines are substantially the same. The present apparatus causes the pressures of the fuel supplied to the respective engines to be equal so that the total load will be equally proportioned between the engines. In the present instance, the pressures which are equalized are the pressures of the fuel in the common supply rails of the respective engines, and such equalization is obtained by automatically varying the pressure of the fuel supplied to engine No. 2 so that it is equal to the pressure of the fuel supplied to engine No. 1.

In the various embodiments shown in the drawings, the load proportioning means functions in response to the fuel pressure supplied to both engines to control the pressure of the fuel supplied to engine No. 2. Thus the load proportioning means 31 is placed in the line connecting the fuel supply apparatus 24 of engine No. 2 with the common supply rail 25 of this engine. Since the setting of the throttle lever 36 for engine No. 2 is slightly higher than that for engine No. l as heretofore mentioned, the load proportioning means 31 automatically reduces the pressure for engine No. 2 to the point where it is equal to that for engine No. 1. The load proportioning means functions as a valve means mounted in the supply conduit of engine No. 2 and having a movable valve member acted upon oppositely by the pressures of the fuel supplied to the respective engines for controlling the flow of fuel to engine No. 2.

One construction of the load proportioning means 31 is shown in Fig. 2 and comprises a cylinder 42 having a port 43 in its side wall intermediate its ends. The port 43 is connected to the line 30 to receive fuel from the fuel supply apparatus 24 for engine No. 2. The cylinder 42 is also provided with a port 44, intermediate its ends and offset from the port 43, which is connected to the line 32 for supplying fuel to the common supply rail 25 of engine No. 2. Within the cylinder 42 is a piston, indicated generally at 45, having a central portion 46 of reduced diameter. Thus fuel can flow from the fuel supply apparatus 24 through the port 43, then through the annular space within the cylinder 42 around the reduced portion 46 of the piston to the port 44 to supply the common supply rail 25 of engine No. 2.

The right-hand end of the cylinder 42 is closed by a plug 47 held in place by a snap ring 48, and the portion of the cylinder between the plug 47 and the right-hand end of the piston communicates with the annular space around the reduced portion 46 by a passage 50 drilled through the right-hand end of the piston. The fuel in the right-hand end of the cylinder will be maintained at the same pressure as the fuel in the annular space around the reduced portion 46 intermediate the ends of the piston.

The left-hand end of the cylinder 42 is closed by a plug 51 held in place by a snap ring 52. The plug 51 is provided with a central port 53 connected by a line 54 with the line 26 which connects the fuel supply apparatus 24 of engine No. l with its common supply rail 25. Thus the pressure exerted against the left end of the piston is the pressure of the fuel supplied to engine No. 1.

When both engines are operating, the pressure of the fuel supplied to engine No. l is transmitted through the line 54 to the left end of the piston 45, thereby tending to move the piston 45 to the right. The pressure of the fuel supplied to engine No. 2 through the load proportioning means 31 enters the annular space about the reduced portion 46 of the piston for flow to the engine and the pressure of the fuel in the annular space is exerted on the right end of the piston due to the passage in the piston. If the piston is in its extreme right-hand position when these pressures are initially established, the slightly higher pressure in the fuel supplied by the fuel supply apparatus for engine No. 2, due to its slightly higher throttle lever setting mentioned above, will tend to move the piston to the left. The port 43, through which fuel enters the cylinder, is so positioned that such movement of the piston to the left will gradually reduce the effective size of the port 43. Such reduction of effective size of the port 43 will result in a reduction in pressure in the annular space about the reduced portion 46 of the piston and hence a reduction in pressure at the right end of the piston. When this pressure is reduced to the point where it equals the pressure from engine No. l acting on the left end of the piston, the pressures at opposite ends of the piston are thereby balanced and the piston will remain in such position. Thus the pressure of the fuel supplied to engine No. 2 will equal the pressure of the fuel supplied to engine No. 1 so that the two engines will thereby carry equal loads.

If, when the pressures are initially established, the piston should be too far to the left so that the port 43 is reduced in effective size to too great an extent, and the pressure supplied to engine No. 2 is thereby less than the pressure of the fuel for engine No. 1, the higher pressure in the left-hand end of the cylinder 42 will cause the piston to move towards the right until the pressure supplied to the engine No. 2 is equal to the pressure of the fuel supplied to engine No. 1. At that point the piston will be balanced with the port 43 of proper effective size to supply fuel to engine No. 2 at the same pressure as the pressure of the fuel supplied to engine No. 1.

When it is desired to operate engine No. 1 alone with engine No. 2 not operating, the shutoff valve 33 is closed to prevent any fuel from being supplied to the cylinders of engine No. 2. Under this condition, while the fuel supplied to engine No. 1 is under pressure, the position of the piston 42 does not effect the fuel pressure for engine No. 1 and hence engine No. l is free for operation under manual control or under whatever governor control is provided without any effect thereon from the load proportioning means 31.

When it is desired to operate engine No. 2 without operating engine No. 1, the shutofi valve 27 for engine No. 1 is closed and no pressure will be exerted on the left end of the piston 45 through the line 54. Since engine No. 2 is operating, the fuel under pressure passes through the annular space about the reduced portion 46 of the piston and such pressure is exerted against the right end of the piston, thus tending to move the piston to its extreme left position. Such movement of the piston closes the port 43 so that no fuel can pass to the cylinders of engine No. 2 through the annular space about the reduced portion 46. To supply fuel to the cylinders of engine No. 2 under this condition, a bypass line 55 (see Fig. 1) is connected to the line 30 from the fuel supply apparatus 24 and to the line 32 leading to the cylinders of engine No. 2 so that fuel can be bypassed around the load proportioning means 31 when engine No. 2 alone is operating. The bypass line 55 includes a shutoff valve 56 which is adapted to be closed when both engines are operating so that the fuel flowing to the cylinders of engine No. 2 will be controlled by the position of the piston 45.

When it is desired to operate three or more engines with all the engines carrying equal proportions of the load, a load proportioning means such .as the means 31 is provided for each additional engine and is connected in the same manner as that shown for engine No. 2. Thus the branch line 23, the return line 35, and the pressure line 54 may all be extended to the 3rd and other engines as indicated by dotted lines in Fig. 1.

The modified construction of the load proportioning means shown in Fig. 3 of the drawing-s is similar to that shown in Fig. 2 but the bypass line, with its valve, for bypassing fuel around the load proportioning means when engine No. 2 alone is operating is incorporated in the load proportioning means. Thus the lines 30, 32 and 54 are connected to the device of Fig. 3 in the same manner as in Fig. 2, and the piston 45 is the same as in Fig. 2. The cylinder, in this instance, has an elongated port 60 to which the line 30 is connected, and extending laterally from the port 66 is an opening 61 leading to a valve chamber 62. The opening 61 is adapted to be opened and closed by a manually operable valve member 63. Extending from the valve chamber 62 to the right end of the cylinder is a passage 64.

When engine No. 2 alone is to operate, and engine No. 1 is shut off by closing the shutoff valve 27, the pressure in the right end of the cylinder acts against the piston 45 to close the port 60. However, by opening the valve member 63, fuel can flow to the cylinders of engine No. 2 through the opening 61, the valve chamber 62 and the passage 64 into the right end of the cylinder. Piston 45 is provided with the passage 56, just as in the Previous form, so that fuel can flow from the fuel supply apparatus 24 for engine No. 2 to the cylinders of this engine. Of course when both engines are operating, the valve member 63 is closed so that the piston 45 can control the effective size of the port as.

The form of load proportioning means illustrated in Figs. 4, 5 and 6 function similarly to the tWo previously described forms when both engines are operating but is provided with means automatically providing a bypass passage when engine No. 2 alone is to operate. Thus the device shown in these three figures comprises a cylinder 70 in which is mounted a piston 71 having a reduced portion 72 intermediate its ends. The left end of the cylinder 79 is closed by a plug 73 having an opening 74 adapted to be connected to the line 54 extending from engine No. 1. Intermediate its ends, the cylinder 70 is provided with a port 75 adapted to be connected to the line 3!) extending from the fuel supply apparatus 24 for engine No. 2, and a port '76 adapted to be connected by the line 32 extending to the common supply rail 25 for engine No. 2. The right end of the piston 71 has an annular groove 77 formed therein, which provides a land 80 between the groove 77 and the annular space about 76 the reduced portion 72 of the piston. A passage 81 is drilled through the land and the right end portion of the piston so that the pressure of the fuel in the annular space about the reduced portion 72 will be transmitted to the light end of the cylinder to act on the right end of the piston.

When engine No. 1 alone is operating, and engine No. 2 is shut off by closing the shutoff valve 33, the pressure in the left end of the piston from the fuel supply apparatus for engine No. l forces the piston 71 to its extreme right position as illustrated in Fig. 4. Since the shutoff valve 33 for engine No. 2 is closed, no fuel will flow to the cylinders of engine No. 2, and the position of the piston 71 does not affect the flow of fuel to the cylinders of engine No. 1. When both engines are operating, the pressure of the fuel supplied to engine No. l is applied to the left end of the piston 71. At the same time, the fuel flowing to engine No. 2 passes through the port 75, the annular space about the reduced portion 72 of the piston, and through the port 76, and the pressure of the fuel is applied to the right end of the piston through the hole 81 in the land 8t) and in the end portion of the piston. Since the fuel setting of engine No. 2 is slightly higher than for engine No. 1, the piston 71 will be moved towards the left and the land 84 will partially close the port 75 to reduce the effective size thereof, as shown in Fig. 5. Thus the pressure in the annular space about the reduced portion 72 and in the right end of the cylinder will be reduced until it is equal to the pressure in the left end of the cylinder. Consequently the two engines will carry equal loads.

When engine No. l is shut off by closing the cutoff valve 27, there will be no fuel pressure in the left end of the cylinder 7%. The pressure of the fuel in the right end of the cylinder will thus shift the piston 71 to its extreme left position, as shown in Fig. 6. Under this condition, the land 80 moves beyond the port 75 so that the groove 77 registers with the port 75. Fuel may thus flow to the cylinders of engine No. 2 from the port 75 through the groove 77, and the hole 81 to the port 76.

The load proportioning devices heretofore described are adapted for use with engines which are of the same size and rating. However, a device utilizing the same principles may be employed for engines of different size as illustrated in Fig. 10. While all of the forms of load proportioning means heretofore described may be modified for use with engines of different size, I have illustrated in Fig. 7 a device similar to that illustrated in Fig. 2 as an example. With the device shown in Fig. 7, it is assumed that engine No. 1 is the smaller of the two engines and has a lower power rating than engine No. 2. The operation of the device is exactly the same as that described for the device of Fig. 2, the only difference being that the left end of the piston, indicated at 82, is larger than the right end of the piston, indicated at 83. The diameters of these two ends of the piston are such that the rail pressure of engine No. 1 times the effective area of the larger portion 82 is equal to the rail pressure of engine No. 2 times the effective area of the smaller portion 83 of the piston when the two engines carry their correct proportions of the total load.

The load proportioning means shown in Figs. 8 and 9 is of such construction that the need for a bypass passage when. engine No. 2 alone is operating, is eliminated. As shown in these two figures, the load proportioning device comprises a cylinder having a port 91 adapted to be connected to the line 30 extending from the fuel supply apparatus 24 for engine No. 2. It is also provided with a port 92 adapted to be connected to the line 32 for supplying fuel to the cylinders of engine No. 2. The right end of the cylinder 90 is closed by a plug 23, and within the cylinder is mounted a piston 94 having a reduced central portion 95. The left end of the cylinder 90 is closed by a plunger 96 having a knob 97 on its outer end, with a spring 100 interposed between the end of the cylinder and the knob 97. The plunger 96 when in its outermost position is held against outward movement by a cross pin 101 engaging a shoulder 102 formed by flattening the outer end portion of the plunger. When the plunger 96 is in its outermost position, as illustrated in Fig. 8, the plunger uncovers a port 103 which is adapted to be connected to the fuel supply apparatus of engine No. 1 by the line 54.

When both engines are operating, the pressure of the fuel supplied to engine No. 1 is applied to the left end of the piston 94 through the port 103. The fuel flowing through the line 36 from the fuel supply apparatus 24 for engine No. 2 flows through the port 91 into the annular space about the reduced portion 95 of the piston and then out through the port 92 through the line 32 to the cylinders of engine No. 2. The pressure of the fuel existing in the annular space about the reduced portion 95 is transmitted to the right end of the cylinder and applied to the right end of the piston through a radial passage 104 and an axial passage 1W5. setting of the throttle lever 36 for engine No. 2 being slightly higher than that for engine No. 1, the piston will be moved towards the left until it partially closes the port 91, as illustrated in Fig. 8. When the port M has been partially closed to a sufficient extent so that the pressure in the right end of the cylinder equals that in the left end of the cylinder, the piston will remain at that point and equal pressures of fuel will be applied to both engines, thus balancing the load carried by the respective engines.

When it is desired to operate engine No. 2 alone, the shutoff valve 27 for engine No. 1 is closed as in the former cases. Under such condition, no pressure would be applied against the left end of the piston, and consequently the pressure against the right end of the piston would tend to shift it to the left so far that the port 91 would be closed so that no fuel could flow to the cylinders of engine No. 2. To prevent this, the plunger 96 is adapted to be positioned to hold the piston 94 in its extreme right position so that the port 91 will remain open. To accomplish this, the plunger 96 is pushed inwardly, compressing the spring 100, and then is turned to bring the flattened side which provides the shoulder 102 out of register with the cross pin 101. The cross pin 101 will thereby engage the end of the plunger, as illustrated in Fig. 9, to hold the plunger inits right-hand position. The plunger 96 is of sufficient length so that the inward movement thereof forces the piston 94 to the right and holds With the fuel it in such position so that the port 91 will remain open.

From the foregoing description, it will be evident that I have provided a novel load proportioning means adapted for use with two or more engines where the engines are all rigidly connected to a single driving element or where they are non-rigidly connected thereto or where each engine drives a separate driven element. The device may be constructed either for equally proportioning the load between two or more engines of equal size and rating or to properly proportion the load between two or more engines of unequal size and rating. The device is such that all engines may be operated together or any one of the engines may be operated separately while the other engines are inactive. The device provides satisfactory engine operation at idling speed either when one or all are operating, and permits full governor control of the respective engines at both idling and maximum speeds.

I claim:

1. A multiple engine installation comprising at least two multicylinder internal combustion engines, each of the type in which the power output of the engine is proportional to the pressure of a combustion fluid in a supply conduit connected to the cylinders and each having a throttle lever, the throttle levers of both engines being adapted to be connected to a master throttle for simultaneous movement thereby of both throttle levers, and a load proportioning device mounted in the supply conduit of one engine and connected to the supply conduit of the other engine and comprising means responsive to the pressures of the combustion fluid in the supply conduits of both engines for controlling the pressure of the combustion fluid supplied to the cylinders of said one engine, the throttle lever of one engine being set to provide a slightly greater force on said means due to the pressure of the combustion fluid than the other engine for a given movement of the throttle levers.

2. A multiple engine installation comprising at least two multicylinder internal combustion engines, each of the type in which the power output of the engine is proportional to the pressure of a combustion fluid in a supply conduit connected to the cylinders and each having a throttle lever, the throttle levers of both engines being adapted to be connected to a master throttle for simultaneous movement thereby of both throttle levers, and a load proportioning device comprising valve means mounted in the supply conduit of one engine and connected to the supply conduit of the other engine and having a movable valve member oppositely acted upon by the pressures of the combustion fluid supplied to the respective engines for controlling the pressure of the combustion fluid supplied to said one engine, the throttle lever of said one engine being set to provide a slightly greater force on said valve member due to the pressure of the combustion fluid than the other engine for a given movement of the throttle levers.

3. A multiple engine installation comprising at least two multicylinder internal combustion engines, each of the type in which the power output of the engine is proportional to the pressure of a combustion fluid in a supply conduit connected to the cylinders and each having a throttle lever, the throttle levers of both engines being adapted to be connected to a master throttle for simultaneous movement thereby of both throttle levers, and a load proportioning device comprising a cylinder connected in the supply conduit of said one engine with the flow to said engine passing therethrough, a piston movable in said cylinder to control the flow therethrough to said one engine, said cylinder also being connected to the supply conduit of the other engine and said piston thereby being movable in response to the pressures in both supply conduits, the throttle lever of said one engine being set to provide a slightly greater force on said piston due to the pressure of the combustion fluid than said other engine for a given movement of the throttle levers.

4. A multiple engine installation comprising at least two multicylinder internal combustion engines, each of the type in which the power output of the engine is proportional to the pressure of fuel supplied to the cylinders by a fuel supply means provided with a throttle lever, the throttle levers of both engines being adapted to be actuated by a master throttle for simultaneous movement thereby, and a load proportioning device comprismg a cylinder connected intermediate its ends to the fuel supply means for one engine and to said one engine for the flow of fuel through said cylinder to said one engine and connected at one end to the fuel supply means of the other engine, and a piston mounted in said cylinder and arranged to control the flow to said one engine and movable in response to the pressure of the fuel flowing through said cylinder to said one engine and the pressure of the fuel from the fuel supply means of the other engine, the throttle lever of said one engine being set to provide a slightly greater force on said piston due to the pressure of the fuel than the other engine for the same movement of both throttle levers.

5. A multiple engine installation comprising at least two multicylinder internal combustion engines, each of the type in which the power output of the engine is proportional to the pressure of fuel supplied to the cylinders by a fuel supply means provided with a throttle .lever, the throttle levers of both engines being adapted to be actuated by a master throttle for simultaneous movement thereby, and a load proportioning device comprising a cylinder having a pair of openings intermediate its ends and respectively connected to one engine and to the fuel supply means for said one engine for the flow of fuel through said cylinder to said one engine, said cylinder having an opening in one end connected to the fuel supply means of the other engine, and a piston in said cylinder having a reduced portion intermediate its ends to permit flow through said cylinder to said one engine, said piston being subjected at one end to the pressure of the fuel flowing to said other engine, the other end of the piston having a passage therethrough from the space in the cylinder about said reduced portion to subject said other end of the piston to the pressure of the fuel flowing to said one engine, the throttle lever for said one engine being set to provide a slightly greater force on said piston due to the pressure of the fuel than the other engine for the same movement of both throttle levers, the piston being movable thereby to partially close the opening connected to the fuel supply means of said one engine to equalize the forces on said piston.

6. A multiple engine installation comprising at least two multicylinder internal combustion engines, each of the type in which the power output of the engine is proportional to the pressure of fuel supplied to the cylinders by a fuel supply means provided with a throttle lever, the throttle levers of both engines being adapted to be actuated by a master throttle for simultaneous movement thereby, and a load proportioning device comprising a cylinder having a piston therein and connected at one end to the fuel supply means of one engine to subject the associated end of the piston to the pressure of the fuel flowing to said engine, said piston intermediate its ends having a reduced portion to provide space in the cylinder between the ends of the piston, said piston having a passage through its other end extending from said space to the other end of the cylinder to subject said other end of the piston to the pressure in said space, said cylinder having a first opening into said space adjacent said other end of the piston and partially closable thereby, said opening being connected to the fuel supply means for the other engine, said cylinder having a second opening into said space beyond the range of movement of both ends of the piston so that it remains fully open, said second opening being connected to said other engine, the throttle lever for said other engine being set to provide a slightly greater force on said piston than said one engine for the same movement of both throttle levers, the piston being movable thereby to partially close said first opening to equalize the forces on said piston.

7. A multiple engine installation comprising at least two multicylinder internal combustion engines, each of the type in which the power output of the engine is proportional to the pressure of a combustion fluid in a supply conduit connected to the cylinders and each having a throttle lever, the throttle levers of both engines being adapted to be connected to a master throttle for simultaneous movement thereby of both throttle levers, and a load proportioning device comprising valve means mounted in the supply conduit of one engine and connected to the supply conduit of the other engine, said valve means including a movable valve member acted upon oppositely by the pressures of the combustion fluid in the respective supply conduits for controlling the flowthrough said valve means to. said one engine, said valve member tending to shut off the flow to said one engine when said other engine is rendered inoperative, and bypass means for supplying fuel to said one engine when said valve member shuts ofi the flow thereto.

8. A multiple engine installation comprising at least two. multicylinder internal combustion engines, each of the type in which the power output of the engine is proportional to the pressure of fuel supplied to the cylinders by a fuel supply means provided; with a throttle lever, the throttle levers of both engines being adapted to be actuated by a master throttle for simultaneous movement thereby, and a load proportioning device comprising a cylinder having a pair of openings intermediate its ends and respectively connected to one engine and to the fuel supply means for said one engine for the flow of fuel through said cylinder to said one engine, said cylinder having an opening in one end connected to the fuel supply means of the other engine, and a piston in said cylinder having a reduced portion intermediate its ends to permit flow through said cylinder to said one engine, said piston being subjected at one end to the pressure of the fuel flowing to said other engine, the other end of the piston having a passage therethrough from the space in the cylinder about said reduced portion to subject said other end of the piston the the pressure of the fuel flowing to said one engine, said piston being movable to close the opening connected to the fuel supply means of said one engine when said other engine is rendered in operative, and bypass means connected to the fuel supply means of said one engine for supplying fuel to said one engine when said opening is closed.

9. A multiple engine installation comprising at least two multicylinder internal combustion engines, each of the type in which the power output of the engine is proportional to the pressure of a combustion fluid in a supply conduit connected to the cylinders and each having a throttle lever, the throttle levers of both engines being adapted to be connected to a master throttle for simultaneous movement thereby of both throttle levers, and a load proportioning device comprising valve means mounted in the supply conduit of one engine and connected to the supply conduit of the other engine, said valve means including a movable valve member acted upon oppositely by the pressures of the combustion fluid in the respective supply conduits for controlling the flow through said valve means to said one engine, said valve member tending to shut off the flow to said one engine when said other engine is rendered inoperative, and a valve-controlled bypass line extending around said valve means for supplying fuel to said one engine when said valve member shuts off the flow therethrough.

10. A multiple engine installation comprising at least two multicy-linder internal combustion engines, each of the type in which the power output of the engine is proportional to the pressure of a combustion fluid in a supply conduit connected to the cylinders and each having a throttle lever, the throttle levers of both engines being adapted to be connected to a master throttle for simultaneous movement thereby of both throttle levers, and a load proportioning device comprising valve means mounted in the supply conduit of one engine and connected to the supply conduit of the other engine, said valve means including a movable valve member acted upon oppositely by the pressures of the combustion fluid in the respective supply conduits for controlling the flow through said valve means to said one engine, said valve member tending to shut off the flow tosaid one engine when said other engine is rendered inoperative, said valve means having a bypass passage around said valve means for supplying fuel to said one engine when said valve member shuts off the flow of fuel thereto, and a manually operable valve for opening and closing said bypass passage.

11. A multiple engine installation comprising at least two multicylinder internal combustion engines, each of the type in which the power output of the engine is proportional to the pressure of fuel supplied to the cylinders by a fuel supply means provided with a throttle lever, the throttle levers of both engines being adapted to be actuated by a master throttle for simultaneous movement thereby, and a load proportioning device comprising a cylinder having a pair of openings intermediate its ends and respectively connected to one engine and to the fuel supply means for said one engine for the flow of fuel through said cylinder to said one engine, said cylinder having an opening in one end connected to the fuel supply means of the other engine, and a piston in said cylinder having a reduced portion intermediate its ends to permit flow through said cylinder to said one engine, said piston being subjected at one end to the pressure of the fuel flowing to said other engine, the other end of the piston having a passage therethrough from the space in the cylinder about said reduced portion to subject said other end of the piston to the pressure of the fuel flowing to said one engine, said piston being movable to close the opening connected to the fuel supply means of said one engine when said other engine is rendered inoperative, said cylinder having a bypass passage connected to the fuel supply means for said one engine and to the other end of said cylinder for supplying fuel to said one engine when said piston closes said opening, and a manually operable valve for opening and closing said bypass passage.

12. A multiple engine installation comprising at least two multicylinder internal combustion engines, each of the type in which the power output of the engine is proportional to the pressure of fuel supplied to the cylinders by a fuel supply means provided with a throttle lever, the throttle levers of both engines being adapted to be actuated by a master throttle for simultaneous movement thereby, and a load proportioning device comprising a cylinder having a pair of ports intermediate its ends, one of said ports being connected to the fuel supply means for one engine and the other port being connected to said one engine for the flow of fuel through said cylinder to said one engine, said cylinder also having a port at one end connected to the fuel supply means of the other engine, and a piston in said cylinder having a reduced intermediate portion providing a space in the cylinder normally open to said pair of ports, and two end portions one of which is subjected to the pressure of the fuel from the fuel supply means of said other engine and the other of which has a passage extending therethrough to subject said other end portion to the pressure of the fuel in said space, said piston being movable when the pressure on said other end portion of the piston is greater than the pressure on said one end portion to move said other end portion over said port connected to the fuel supply means for said one engine, and a groove in said other end portion communicating with said passage and with said port connected to the fuel supply means for said one engine when said other engine is rendered inoperable, to supply fuel to said one engine.

13. A multiple engine installation comprising at least two multicylinder internal combustion engines, each of the type in which the power output of the engine is proportional to the pressure of fuel supplied to the cylinders by a fuel supply means provided with a throttle lever, the throttle levers of both engines being adapted to be actuated by a master throttle for simultaneous movement thereby, and a load proportioning device comprising a cylinder intermediate its ends having a first port connected to the fuel supply means for one engine and a second port connected to said one engine for the flow of fuel through said cylinder to said one engine and connected at one end to the fuel supply means of the other engine, and a piston mounted in said cylinder and arranged to control the flow from said first port to said second port and movable in response to the pressure of the fuel flowing through said cylinder to said one engine and the pressure of the fuel. from the fuel supply means of the other engine, said piston having a passage communicating with said second port and registering with said first port when said other engine is rendered inoperable, to supply fuel to said one engine.

14. A multiple engine installation comprising at least two multicylinder internal combustion engines, each of the type in which the power output of the engine is proportional to the pressure of fuel supplied to the cylinders by a fuel supply means provided with a throttle lever, the throttle levers of both engines being adapted to be actuated by a master throttle for simultaneous movement thereby, and a load proportioning device comprising valve means connected to the fuel supply means for one engine and to said one engine for flow of fuel therethrough to said one engine from said fuel supply means and connected to the fuel supply means for the other engine, said valve means including a movable valve member oppositely acted upon by the pressures of the fuel supplied to the respective engines, said valve member having a passage communicating with said one engine, and said valve member being movable by the pressure of the fuel supplied to said one engine when said other engine is rendered inoperable, to connect said passage with the fuel supply for said one engine.

15. The combination of claim 5 further characterized in that, with two engines having different power output ratings and a corresponding difference in fuel pressures, one end portion of the cylinder is larger than the other and the end portions of the piston are correspondingly dimensioned, and the cylinder is so connected that the larger end of the piston is subjected to the pressure of the fuel for the smaller engine and the smaller end of the piston is subjected to the pressure of the fuel for the larger engine.

16. The combination of claim 2 further characterized by the provision of means for holding said valve member against movement by the pressure of the combustion fluid supplied to said one engine when said other engine is rendered inoperable, to permit flow of combustion fluid through said valve means to said one engine.

17. The combination of claim 2 further characterized by the provision of a manually lockable member movable into engagement with said valve member for holding said valve member against movement by the pressure of the combustion fluid supplied to said one engine when said other engine is rendered inoperable, to permit flow of combustion fluid through said valve means to said one engine.

18. The combination of claim 3 further characterized by the provision of a manually movable member mounted in one end of said cylinder and engageable with said piston for holding said piston against movement by the pressure of the combustion fluid supplied to said one engine when said other engine is rendered inoperable, to permit flow of combustion fluid through said cylinder to said one engine, spring means mounted on said cylinder and tending to move said manually movable member out of engagement with said piston, and means for locking said manually movable member in engagement with said piston.

19. The combination of claim 6 further characterized by the provision of a manually movable plunger mounted in said one end of the cylinder and engageable with said piston for holding said piston against movement by the pressure of the fuel supplied to said other engine when said one engine is rendered inoperable, to permit flow of fuel through said cylinder to said other engine, spring means mounted in said one end of the cylinder and tending to move said plunger out of engagement with said piston, and means engageable by rotative movement of said plunger for locking said plunger in engagement with said piston.

20. The combination of claim 7, in which said bypass means comprises a bypass passage in said valve member.

References Cited in the file of this patent UNITED STATES PATENTS 1,867,649 Brush July 19, 1932 2,062,824 Rockwell et al Dec. 1, 1936 2,669,837 Harris Feb. 23, 1954 FOREIGN PATENTS 265,290 Switzerland Feb. 16, 1950 

